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If LaMarcus Were a Computer Program

I’m generally amused/irritated with discussions of streaks, hot hands, bad starts, and other events. Statistically, this doesn’t really make any sense. One of the great books I’ve read recently on the subject was specifically aimed at sports and called “Scorecasting” (recommended from someone on this blog, I might add—thank you).

This is particularly acute with the recent road trip and poor, lambasted Felton and beleaguered McMillan.

Let’s see if we can put this in a way that can help reveal the lie of our intuition disguising the mathematical realities.

We’re all familiar with streaks on the roulette table or games of Risk. This leads to the “gambler’s fallacy” that has been discussed at length elsewhere on this website. But let’s apply it to sports.

Let’s assume a hypothetical LaMarcus Aldridge. We’ll call him Excel Aldridge. Let’s further assume that he’s shooting a pure 45% from the field: every single shot he takes has a 45% chance of scoring. We could assume that he takes a pure 30 shots a game but let’s insert another bit of randomness—let’s assume that each shot only has a 70% chance of being “born” because of offensive vagaries, defensive pressure, or whatever. Let’s finally assume that LMA gives 100% effort every single play so his shooting percentage never deviates and he takes every shot the offense gives him.

Statistically, this would mean LMA would take 21 shots every game, scoring 18.9 points—throw in some number of free throws and you have an easy all-star level player.

Finally, let’s assume a hypothetical hysterical beat reporter named Jeffrey Nimble. How might the first series of games gone down? Let’s let MS Excel throw spit out some random numbers and see:

Game 1: Aldridge is off to a bad start to the season scoring 16 points but needing 25 shots to do it. He missed his first 3 shots and eventually missing 11 of his first 13. McMillan doggedly kept feeding the post and Aldridge turned it around in the second half. 8/25 for 32% shooting percentage.

Game 2: Aldridge rebounds the next night with a workmanlike 22 point outing in game 2, going 4 of 6 to start the game and drilling the opponent at the end of the game with four straight makes in crunch time when it mattered most. 11/23 for 48% shooting percentage.

Game 3: Aldridge’s struggle with his shooting return even though he scored 18 points. Late in the second half he faded missing 5 of his last 6 shots including all 4 close end the game. 9/25 for 36%

Game 4: Aldridge dominates at last with a 28pt outburst controlling the paint all night. He was consistent with his shot all game long finishing 14/28 for a pure 50%. This is exactly what the Blazers need him to do every night.

Game 5: Aldridge finishes the game with an average-for-him 20 points. He started out hot in the first half hitting all five of his first shots. But once again we see him fading—possibly due to the condensed schedule and the back-to-back night—at one point missing 9 straight shots and showing visible frustration. 10/24 for 42% from the field.

This is me forcing a fictional narrative on to absolute random chance according to MS Excel’s random number generator. Just like we predicted, Excel LMA is averaging 20.8 points per game and shooting 48% from the field. But in that stretch he two occasions of 8+ misses in a row. Reading into mathematical fiction like this is like lazy reporting from a box score and hardly enlightening.

Why go through this exercise? Sports is a pursuit where we’re attaching a narrative to statistical probability and this is fun—just like gambling is fun—but it’s fraught with errors in judgment. Understanding the difference between a perfectly normal streak and a developing penchant for turnovers or a developing accuracy in 3 point shooting is a big problem. It’s a place where I try to give the benefit of the doubt to the coaching staff. We see Nolan take maybe 3 shots in a game. That’s way too small a size to make a judgment. Nate sees Nolan take hundreds of shots in practice—he has a much better read.

What I have come to do is respect offenses and systems. Are the Blazers getting open shots? Are they getting shots in motion? Shots off assists? Or are they taking flaming bag shots or isolation shots? I love seeing our defensive and offensive systems work because those systems are generating better statistical probabilities. This is good coaching.

I am not alarmed when a good shooter misses several in a row if they’re good shots. Is he resilient? Does he let it affect him? Do a few misses rattle him? These are the danger signs. Good players, I think, instinctively understand this… fans would have a lot less heartache if they did too. Good coaching creates players who do not get down on themselves when streaks develop.

Does Nate meet these two criteria? Yes, I think he does.

Comment 16 comments  |  10 recs  | 

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It's a bit like poker.

You have coolers and bad beats, but you keep playing because if you’re good, it will statisically even out.

by ktngo09 on Jan 19, 2012 9:15 PM PST reply actions  

It´s also like poker because the outcome depends also on your opponent, not only in your capacities and effort.

Following other teams (Nuggets and Wolves because of Ricky and Rudy) I have understood that I was looking at my team and players as they would be fishes in a tank. Well, they are in the open see and they don´t look like contenders and have a lot of flaws. That´s why I want to rebuild. If LA were a program he would be placed in an inefficient computer.

by amlmart1 on Jan 19, 2012 11:01 PM PST up reply actions  

ew.

"We gotta get this $#!^ together guys!" - Phil

by 420Phenom on Jan 20, 2012 12:13 AM PST reply actions  

Shooting percentage is a historical statistic.

It has no impact on the future and is not a probability.

It only tells you how many shots have been made in the past. You need to keep the context attached to a stat, for it to be of any use at all.

by manfredi on Jan 20, 2012 7:31 AM PST reply actions  

Shooting percentage is a historical stat, sure.

But I’d imagine it’s correlation year over year is good enough to make it predicative.

by joof on Jan 20, 2012 3:41 PM PST up reply actions  

Exactly

More data is always helpful. If two people, one with access to the stats and one just using their intuition, were to guess what an NBA player’s shooting percentage over the season would be, it’s far more likely that the person with the data will be right in the end. It’s obviously different than something like a coinflip, but let’s not completely overreact and swing wildly to saying it has no predictive value whatsoever. Obviously small amounts of data (like for one or two seasons) will be less accurate than for guys that have been in the league for a while, but they’re still helpful.

by Royster on Jan 20, 2012 4:01 PM PST up reply actions  

Bad Start

I’m confused because what you described in some cases would be exactly what many people mean when they say “Bad start” or “Hot start.” It seems to me that kind of language indicates awareness that the player is better than the numbers show (or worse), but that they are in the midst of one of the bad stretches that come along with any statistical variance.

The conclusion that it seems you are trying to warn against is that we would say “he no longer can shoot the ball well.” In other words believing that this will not even out.

Using your random number generator you had times where Excel Aldridge made several consecutive shots. Wouldn’t that be a streak? I don’t understand your aversion to that kind of language when you clearly understand that it happens.

I do like your conclusion about systems, Nate’s perspective and taking good shots.

by MavetheGreat on Jan 20, 2012 2:06 PM PST reply actions  

Yes...

You’re right. I’m not suggesting that streaks don’t happen but rather than we attribute far too much meaning to them. It’s fun at blackjack when I get 4 naturals in a row: nice streak! I might even—after a few cocktails—refer to the table as “hot” and seek it out the next night knowing full well that it’s a mathematical fiction.

Same rules apply to watching basketball. It’s fun (or not) to watch a streak develop but it’s not how you build a team, assess an offense, or evaluate a coach. Lots of the panic and tumult I see after a game is focused on streaks that developed when the team was actually creating perfectly acceptable and reasonable shots.

Buck Williams for the hall of fame

by Phizbin on Jan 21, 2012 5:46 AM PST up reply actions  

LOL

That’s my whole point in a cartoon! I am humbled. Rec .

Buck Williams for the hall of fame

by Phizbin on Jan 21, 2012 5:43 AM PST up reply actions  

+1000000

so true, needed to be said

by prezofdeath on Jan 23, 2012 1:23 PM PST reply actions  

If LMA were a program...

He’d be Microsoft Word. Expensive, sometimes failing expectations, but sometimes excellent, and the choice most people end up making for word processing.

"Say his NAME, Portland. Gerald Wallace is...awesome." -Dave, 4/9/11

by austinpwnz on Jan 23, 2012 1:37 PM PST reply actions  

For the Last Time, LMA is not SOFTware!

And he certainly isn’t micro. So he can’t be MICROSOFT.

So what is LaMarcus?

MACROHARD!

Now all we need is the rest of the roster to get into "how can everybody help Nicco and Oden" mode. -- Oden Mad, Oden Smash! Sep 29, 2010 7:47 PM

by LaoTzu on Jan 23, 2012 10:46 PM PST reply actions  

Rec - thanks for the thoughtful post

Its success rate was 2 solid standard deviations from the norm!

Holding out for Devyn

by T$ 225 on Jan 23, 2012 10:49 PM PST reply actions  

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